The present invention discloses a double-power energy saving system of rubber tire gantry crane (RTG), which is composed of a controller, a battery pack, a generator set and so on. The system changed the power supply mode of traditional RTG which is powered by a single generator set or a superposition of a generator set and a battery pack. Both the battery pack and the generator set of the system can support the RTG operations independently, forming the double-power energy saving system to improve the equipment reliability. The battery pack is used as the primary power source for RTG and the output power can be highly matched with the demanded power, which reduces the reactive loss and increases the energy efficiency. The generator set is shut down and the power is supplied by the battery pack when the electricity of the battery pack is high; the generator set is started to supply power directly for RTG when the electricity of the battery pack is low, and the surplus energy can charge the battery pack. Once the battery pack is put into operation, it will run in the best economical fuel consumption area to achieve the highest fuel efficiency. The feedback energy of RTG can be fully recovered because the charging power of the battery pack is larger than the maximum feedback energy power of RTG. It is not required to replace the original generator set of RTG when the system is applied to RTG transformations.

An electric winch device includes a required braking force estimation section which estimates a required braking force required to stop a free-falling object at a position at an allowable stopping height; a braking force determination section which determines, out of an operational braking force, each of a first braking force to be borne by a braking device and a second braking force to be borne by a braking force which is generated in an electric motor due to consumption of regenerative power; and a control section which causes the braking device to apply the first braking force to a winch drum. The braking force determination section determines the first braking force to be a braking force equal to or greater than the required braking force when, at a time of stopping of the free-falling object, the operational braking force is equal to or greater than the required braking force.

An electric winch device includes a required braking force estimation section which estimates a required braking force required to stop a free-falling object at a position at an allowable stopping height; a braking force determination section which determines, out of an operational braking force, each of a first braking force to be borne by a braking device and a second braking force to be borne by a braking force which is generated in an electric motor due to consumption of regenerative power; and a control section which causes the braking device to apply the first braking force to a winch drum. The braking force determination section determines the first braking force to be a braking force equal to or greater than the required braking force when, at a time of stopping of the free-falling object, the operational braking force is equal to or greater than the required braking force.

The disclosure relates to a work machine, comprising a primary energy source for feeding electric energy into a link, a gear for performing a task of the work machine, at least one electric drive connected to the link in order to operate the gear of the work machine, a holding brake for fixing or releasing the gear, and an energy store which is connected to the link in order to provide electric energy demanded from the link upon actuation of a gear and/or to absorb electric energy fed into the link. According to the disclosure, during an emergency lowering of the gear, the at least one electric drive to convert the kinetic energy into electric energy and to feed it into the link. In the event of an unavailability or failure, the primary energy source is configured to absorb the energy fed into the link by the electric drive.

An electric winch device including an electric motor that rotates a winch drum in a hoisting direction, and generates regenerative electric power when a rotation of the winch drum in a lowering direction is transmitted to the electric motor, a transmission device that transmits the rotation between the electric motor and the winch drum, a power calculating section that calculates power of the target object by freefall, and a control section that controls an operation of the transmission device. When the power calculated by the power calculating section exceeds reference electric power, the control section causes the transmission device to change the transmission rate of the rotation to a transmission rate at which the regenerative electric power generated by the electric motor is equal to or smaller than the reference electric power.

An electric winch device including an electric motor that rotates a winch drum in a hoisting direction, and generates regenerative electric power when a rotation of the winch drum in a lowering direction is transmitted to the electric motor, a transmission device that transmits the rotation between the electric motor and the winch drum, a power calculating section that calculates power of the target object by freefall, and a control section that controls an operation of the transmission device. When the power calculated by the power calculating section exceeds reference electric power, the control section causes the transmission device to change the transmission rate of the rotation to a transmission rate at which the regenerative electric power generated by the electric motor is equal to or smaller than the reference electric power.

In a system and method for operating a system, which includes a first inverter which feeds a first electric motor, and a second inverter which feeds a second electric motor, the DC-voltage side connection of the first inverter is connected to the DC-voltage side connection of a rectifier which is supplied from an electrical AC-voltage supply network, the DC-voltage side connection of the second inverter is connected to the DC-voltage side connection of the rectifier, in particular, the two DC-voltage side connections of the inverters are switched in parallel, and a controller is provided, in particular in the first inverter, which controls the current accepted and acquired by the first inverter at its DC-voltage side terminal toward a setpoint value in that the torque of the first electric motor fed by the first inverter is the controlled variable.

An elevator cage is used in an energy storage and delivery system to move blocks between a lower elevation of a tower and a higher elevation of a tower to store energy and to move blocks between a higher elevation of the tower and a lower elevation of the tower under force of gravity to generate electricity. The elevator cage removably receives a block thereon and supports the block on at least three sides.

The present invention comprises an electrified construction and/or material handling machine, in particular a crane, with electric drives for driving working assemblies, an electric energy store for supplying the electric drives with power, and a charging device for recharging the energy store, wherein the charging device has various charging interfaces for charging the energy store from various power supplies comprising at least one machine-integrated power generator and an external power supply.